9:30 AM - 9:45 AM
[AAS04-02] The 60 years history of atmospheric formation pathways responsible for sulfate based on triple oxygen isotopic composition of sulfate preserved in SE-Dome ice core
Keywords:stable isotope, Sulfate, Triple oxygen isotopes, Chemical feedback
To help address this, here we use mass-independent oxygen isotopic composition (Δ17O) of sulfate providing insight into past oxidation pathways responsible for sulfate formation. We present Δ17O of SO42− obtained from a 90.45 m depth ice core drilled at a high-elevation dome site in southeast Greenland called SE-Dome, covering the last 60 years. We found that Δ17O of SO42− with low during the 1960s-1970s and high in after the 2000s. This increase in Δ17O of SO42− indicates that sulfate formation pathways responsible for sulfate changed after 1960 to the present along with declining SO2 emission. In the presentation, we will discuss the enhanced role of a oxidation processes contributing to increase Δ17O of SO42−, and its implication to the changes in atmospheric chemistry though the changes in anthropogenic activities. This provides insight into direct and indirect effects of anthropogenic activities to the air quality by changing sulfate formation pathways. These functions, so called “chemical feedback", should be considered for making efficient mitigation policy for climate change and air quality by controlling emission of anthropogenic pollutants.